HBOT is not risk-free. The most familiar problems are pressure-related ear or sinus discomfort, while less common complications can involve the lungs, vision, blood sugar, oxygen exposure, or confinement anxiety. Fire prevention and continuous monitoring are essential.

An untreated pneumothorax is the central absolute contraindication cited in clinical references. Many other conditions and medicines are relative concerns that require individual assessment, possible testing, a delay, or a modified plan.